Choice "C" is correct. Costs are deemed to be relevant if they change as a result of selecting different alternatives. The decision to replace the old van will result in the company paying the purchase price of the new van and receiving the disposal price of the old van. Neither the purchase price of the new van nor the disposal price of the old van will be incurred if the van is not replaced. Ignoring income taxes, the book value of the old van and any potential gain is not relevant.Choice "d" is incorrect. The gain on the sale of the old van is not relevant absent any consideration of taxation.Choice "a" is incorrect. Neither the purchase price of the old van (a sunk cost) nor the gain on the sale of the old van (ignoring tax consequences) are relevant to our decision.Choice "b" is incorrect. Neither the purchase price/accumulated depreciation of the old van (a sunk cost) nor the gain on the sale of the old van (ignoring tax consequences) are relevant to our decision.